Catheter system

ABSTRACT

A catheter system includes a handle and a catheter component operatively connected to the handle for selective adjustment by an actuator associated with the handle housing. The actuator comprises at least in part a generally cylindrical shuttle disposed at least in part within the housing for longitudinal movement. The catheter component is operatively coupled to the shuttle for movement therewith. The shuttle has an outer surface with an annular groove formed therein, and an elastomeric ring seated in the annular groove. An annular slide bearing is retained in the housing, with the shuttle being in part disposed in the annular groove and with the elastomeric ring in frictional contact with the slide bearing. Friction between the elastomeric ring and the slide bearing is sufficient to frictionally retain the shuttle at a selected longitudinal position relative to the housing corresponding to a selected adjustment of the catheter component.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to provisional application Ser. No.61/777,249, filed Mar. 12, 2013, the entire specification of which isincorporated herein.

BACKGROUND OF THE DISCLOSURE

A. Field of the Disclosure

The present disclosure relates generally to a catheter system for use ina human body, and more particularly to a catheter system having at leastone selectively adjustable feature, and still more particularly to acatheter system having multiple control lines associated with multiplecomponents of the system, at least one of which is selectivelyadjustable.

B. Background Art

Catheter systems are well known in the art for use in medicalprocedures, such as diagnostic, therapeutic and ablative procedures.Typical catheter systems generally include an elongate catheterextending from a handle. A physician manipulates the catheter throughthe patient's vasculature to an intended site within the patient. Thecatheter typically carries one or more working components, such aselectrodes or other diagnostic, therapeutic or ablative devices forcarrying out the procedures. Controls or actuators may be provided onthe handle for selectively adjusting one or more characteristics of theworking components.

One particular example of the catheter system is an ablative cathetersystem in which the working component is a multi-electrode componentcarried at the distal end of the catheter. A control wire extends withinthe shaft of the catheter from the electrode component to the handle tooperatively connect the electrode component to an actuator on thehandle. Actuation of the actuator acts on the control wire to configurethe electrode component into a desired configuration. For example, inone such ablative catheter system made by St. Jude Medical, Inc. underthe trade name EnligHTN, the multi-electrode component is in the form ofan electrode basket. Upon locating the electrode basket at a desiredlocation within the patient, actuation of the actuator on the handlepulls on the control wire to reconfigure the electrode from a collapsedconfiguration to an expanded configuration in which the electrodes arein contact with a surface, such as an arterial wall. It is thusimportant to maintain proper tension in the control wire. In somecatheter systems, there may be a need for two or more separate controlwires, such as where there are two or more working components carried bythe catheter. In such an arrangement, it is desirable that propertension in each of the control wires be maintained, particularly whenonly one of the control wires is being acted upon. It is also desirableto maintain a secure connection of the catheter to the handle. It isfurther desirable for the physician to be able to readily actuate theactuator, and for the system to facilitate maintaining the actuator in adesired position corresponding to a desired configuration of a workingcomponent.

BRIEF SUMMARY OF THE DISCLOSURE

In one embodiment, a catheter system generally comprises a handlecomprising a housing having a longitudinal axis, and a catheterconnected to the handle and having a component operatively connected tothe handle for selectively adjusting at least one characteristic of thecatheter component. An actuator is associated with the handle forselectively adjusting the at least one characteristic of the cathetercomponent, and at least in part comprises a generally cylindricalshuttle disposed at least in part within the housing and moveablelongitudinally relative to the housing. The catheter component isoperatively coupled to the shuttle such that longitudinal movement ofthe shuttle relative to the housing adjusts the at least onecharacteristic of the catheter component. The shuttle has an outersurface and an annular groove formed in the outer surface, and anelastomeric ring seated in the annular groove. An annular slide bearingis retained in the housing, with the shuttle being in part disposed inthe slide bearing at the annular groove of the shuttle with theelastomeric ring in frictional contact with the slide bearing. Thefriction between the elastomeric ring and the slide bearing issufficient to frictionally retain the shuttle at a selected longitudinalposition relative to the housing corresponding to a selected adjustmentof the at least one characteristic of the catheter component.

In another embodiment, a catheter system generally comprises a handlecomprising a housing having a longitudinal axis, and a catheterconnected to the handle and having a component operatively connected tothe handle for selectively adjusting at least one characteristic of thecatheter component. An actuator is associated with the handle forselectively adjusting the at least one characteristic of the cathetercomponent. The actuator is digitally manipulatable by an operator usinga single hand and is adjustable from a first position corresponding tothe at least one characteristic of the catheter component to a secondposition corresponding an adjustment of the at least one characteristicof the catheter component. The actuator is frictionally retained in atleast one of the first position and the second position thereof.

The foregoing and other aspects, features, details, utilities andadvantages of the present disclosure will be apparent from reading thefollowing description and claims, and from reviewing the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a catheter system;

FIG. 2 is a side elevation of a catheter and handle of the cathetersystem of FIG. 1, with a distal or front end segment of a catheter shaftdeflected relative to the remainder of the catheter shaft and with aslide actuator in its extended or actuated position corresponding to thedeflection of the catheter shaft;

FIG. 3 is a side elevation similar to FIG. 2, but with the slideactuator in its neutral or unextend position corresponding to thecatheter shaft being undeflected, and with an electrode basket of thecatheter system in an expanded configuration resulting from rotation ofa rotatable actuator;

FIG. 4 is a cross-section of a portion of the handle of the cathetersystem of FIG. 1;

FIG. 5 is a cross-section of another portion of the handle of thecatheter system of FIG. 1;

FIG. 6 is an exploded view of the handle of the catheter system of FIG.1;

FIG. 7 is an enlarged portion of the cross-section of FIG. 4;

FIG. 8 is a cross-section of the handle taken perpendicular to thecross-section of FIG. 7;

FIG. 9 is a top plan view of an assembled worm gear housing, worm gearassembly and pinion member;

FIG. 9A is a top plan view of the worm gear housing,

FIG. 10 is a bottom plan view of the assembled worm gear housing, wormgear assembly and pinion member;

FIG. 10A is a bottom plan view of the worm gear housing;

FIG. 11 is a top plan view of a bottom half of the worm gear housing;

FIG. 12 is an exploded perspective view of a worm gear assembly of thehandle of the catheter system of FIG. 1;

FIG. 13 is a top plan view of a pinion member of the handle;

FIG. 14 is a front elevation of the pinion member of FIG. 13;

FIG. 15 is a bottom plan view of a top half of a barrel housing of thehandle;

FIG. 16 is a top plan view of a bottom half of the barrel housing of thehandle;

FIG. 17 is a top plan view of the bottom half of the barrel housing withthe bottom half of the worm gear housing, the worm gear assembly and thepinion member disposed therein;

FIG. 18 is a top plan view of a bottom half of the handle housing, witha bottom half of the barrel housing and the entire worm gear housing andrelated internal components disposed therein;

FIG. 19 is a top plan view of the bottom half of the handle housing,with the entire barrel housing, worm gear housing and related internalcomponents disposed therein;

FIG. 20 is a top plan view of the bottom half of the handle housing,with the bottom half of the barrel housing, the bottom half of the wormgear housing, the worm gear assembly and the pinion member disposedtherein, the pinion member being in an initial or neutral positioncorresponding to an undeflected configuration (FIG. 1) of the cathetershaft;

FIG. 21 is a top plan view similar to FIG. 20 with the pinion memberpivoted relative to the handle housing to a maximum pivoted positioncorresponding to the maximum deflected configuration (FIG. 2) of thecatheter shaft;

FIG. 21A is an enlarged cross-section of a portion of the handle of FIG.4;

FIG. 22 is a perspective view of a flex relief member of the handle ofthe catheter system of FIG. 1;

FIG. 23 is a rear elevation thereof;

FIG. 24 is a perspective view of a shaft collar of the handle of thecatheter system of FIG. 1;

FIG. 25 is a cross-section thereof;

FIG. 26 is a cross-section thereof taken normal to the cross-section ofFIG. 22; and

FIG. 27 is a perspective cross-section of the flex relief member andshaft collar with the catheter shaft connected thereto.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DETAILED DESCRIPTION OF THE DISCLOSURE

Referring now to the drawings, and in particular to FIGS. 1 and 2, oneembodiment of a catheter system is indicated generally at 21 andincludes a catheter 23, a handle 25 to which the catheter is connected,and a conductor assembly 27 for electrically connecting the cathetersystem to a suitable power supply (not shown).

In the embodiments illustrated and described herein, the catheter system21 includes an elongate flexible catheter 23 that is also selectivelydeflectable (e.g., bendable)—such as at or adjacent the end or tip,broadly referred to as a first working component or first component, ofthe catheter—as illustrated for example in FIG. 2. The catheter system21 also includes what is broadly referred to as a second workingcomponent (or second component). As used herein, a working component isintended to refer to any component that is used for guiding, diagnostic,therapeutic, ablative or other function relating to a patient. Workingcomponents may be carried by the catheter 23 and selectively operated oradjusted. As used in herein, selective operation or adjustment of aworking component is intended to refer to a functional changing of atleast one characteristic of the working component, such as changing theconfiguration of the component, changing the orientation of thecomponent, supplying current to the component, inflating or collapsingthe component or otherwise adjusting, manipulating or operating thecomponent for its intended purpose.

As one example, the catheter system 21 illustrated and described hereinis suitably constructed for use as an ablation system, such as a renalor heart ablation system. More particularly, the illustrated cathetersystem 21 is a multi-electrode renal denervation system. One example ofsuch a system is that currently made by St. Jude Medical, Inc. under thetrade name EnligHTN. General operation of a multi-electrode renaldenervation system is known to those of skill in the art and is notdescribed further herein except to the extent necessary to describe thepresent embodiments. It is understood that the catheter system 21 may beused for any other suitable treatment or purpose without departing fromthe scope of this disclosure. Additionally, while the catheter system 21is illustrated and described herein as including only the flexiblecatheter, the system may further include other components used, forexample, to guide the flexible catheter into the patient—such as,without limitation, a relatively more rigid guide catheter (not shown).

The illustrated catheter 23 of FIG. 1 includes an elongate, flexiblehollow shaft 29 having a central passage and connected to the handle 25at or near a proximal or rear end 31 (not visible in FIGS. 1 and 2 butseen, e.g., in FIG. 7) of the catheter shaft, and an electrode basket 33(broadly, a working component and more broadly a second component of thecatheter system) disposed at or near a distal or front end 35 (or whatis sometimes referred to as the tip) of the catheter shaft. It isunderstood, however, that the electrode basket 33 may be disposedanywhere along the catheter shaft 29 intermediate the rear end 31 andthe front end 35 thereof without departing from the scope of thisdisclosure.

As used herein, the terms proximal and front, and distal and rear, areused with reference to the orientation of the catheter system 21illustrated in the various drawings and for the purpose of describingthe various embodiments set forth herein, and are not intended aslimiting the catheter system and related components to having anyparticular orientation upon assembly or during operation thereof.

The electrode basket 33 is suitably configurable between a collapsedconfiguration (FIG. 1) and an expanded configuration (FIG. 3). Anannular (e.g., ring-shaped) actuator 37 (FIG. 3) is mounted on thehandle 25 for rotation relative thereto and is operatively connected tothe electrode basket 33 for selectively configuring the electrode basketbetween its collapsed and expanded configurations. It is understood thatother suitable actuators (e.g., slide, push button, lever, etc.) may beused instead of the rotating actuator 37 to selectively configure theelectrode basket 33 without departing from the scope of this disclosure.In some embodiments, the electrode basket 33 may be selectivelyadjustable between an infinite number of configurations between itscollapsed and expanded configurations using the actuator 37. A controlline, such as a suitable cable or pull wire 39 (FIG. 4), extends fromthe electrode basket 33 within the hollow catheter shaft 29 and into thehandle 25 and operatively connects the annular actuator 37 with theelectrode basket via a worm gear assembly 306 (FIG. 4 and described infurther detail later herein) to which the pull wire is connected. Whilein the illustrated embodiment a single pull wire 39 is used toselectively configure the electrode basket, it is contemplated that twoor more pull wires, cables or other suitable control lines may be usedfor selectively configuring the electrode basket. It is also understoodthat the control line may be any suitable control line other than a pullwire, such as a cable, string, tie, compression member or other suitableline useful to operatively connect the electrode basket 33 to the wormgear assembly 36 and hence the handle 25.

In the illustrated embodiment, the catheter shaft 29 is also configuredfor deflection near the tip or front end 35 thereof, such as between anundeflected configuration (FIG. 1) and a deflected (e.g., bent orangled) configuration (FIG. 2) for use in guiding the catheter 23 intodesired positions within the patient. As best seen in FIGS. 1 and 2, asuitable slide actuator 41 is mounted on the handle 25 for slidingmovement longitudinally of the handle and is operatively connected tothe deflectable segment of the catheter shaft 29 for movement between afirst or neutral position (FIG. 1) corresponding to the undeflectedconfiguration of the catheter shaft and a second (e.g., extended)position (FIG. 2) corresponding to the deflected configuration of thecatheter shaft. The slide actuator 41 permits the catheter shaft 29 tobe selectively deflected to any number of angular positions between theundeflected configuration and a predetermined maximum deflection (e.g.,angular position) of the catheter. It is understood that any othersuitable actuator (e.g., rotating, push button, lever, etc.) may be usedto selectively adjust (e.g., deflect) the catheter shaft 29 withoutdeparting from the scope of this disclosure.

The electrode basket 33 is suitably configurable between a collapsedconfiguration (FIG. 1) and an expanded configuration (FIG. 3). Anannular (e.g., ring-shaped) actuator 37 (FIG. 3) is mounted on thehandle 25 for rotation relative thereto and is operatively connected tothe electrode basket 33 for selectively configuring the electrode basketbetween its collapsed and expanded configurations. It is understood thatother suitable actuators (e.g., slide, push button, lever, etc.) may beused instead of the rotating actuator 37 to selectively configure theelectrode basket 33 without departing from the scope of this disclosure.In some embodiments, the electrode basket 33 may be selectivelyadjustable between an infinite number of configurations between itscollapsed and expanded configurations using the actuator 37. A controlline, such as a suitable cable or pull wire 39 (FIG. 4), extends fromthe electrode basket 33 within the hollow catheter shaft 29 and into thehandle 25 and operatively connects the annular actuator 37 with theelectrode basket via a worm gear assembly 306 (FIG. 4 and described infurther detail later herein) to which the pull wire is connected. Whilein the illustrated embodiment a single pull wire 39 is used toselectively configure the electrode basket, it is contemplated that twoor more pull wires, cables or other suitable control lines may be usedfor selectively configuring the electrode basket. It is also understoodthat the control line may be any suitable control line other than a pullwire, such as a cable, string, tie, compression member or other suitableline useful to operatively connect the electrode basket 33 to the wormgear assembly 306 and hence the handle 25.

A conductive wire, or more particularly in the illustrated embodiment atwisted bundle 45 of two or more conductive wires (FIG. 4) correspondingto the multiple electrodes of the electrode basket 33, extends from theelectrode basket within the catheter shaft 29 and into the handle 25 forelectrical connection with the conductor assembly 27 to provideelectrical communication between the power supply and the electrodebasket. It is understood that the power supply may be any power supply,such as ultrasonic, RF or other suitable power supply.

With particular reference now to FIGS. 4-6, the handle 25 has alongitudinal or lengthwise axis X and generally comprises an outermosthousing, referred to herein as a handle housing 101, an intermediatehousing, referred to herein as a barrel housing 201 extendinglongitudinally within the handle housing and being slidablelongitudinally relative to the handle housing to broadly define an outershuttle, and an innermost housing, referred to herein as a worm gearhousing 301 extending longitudinally within the barrel housing and beingslidable longitudinally relative to both the barrel housing and thehandle housing to broadly define an inner shuttle. The illustratedhandle housing 101 is of two piece construction (e.g., what is referredto herein as a top half 103 and a bottom half 105 of the handlehousing). However, the handle housing 101 may be of any suitablealternative construction, such as of a single-piece construction or ofmore than two pieces.

The handle housing 101 has a distal or rear end 107 (FIG. 5) to whichthe conductor assembly 27 is connected in any suitable manner. In theillustrated embodiment of FIG. 5, for example, connection is by aninward tapered collar 109 at the rear end 107 of the handle housing 101seating within an annular channel 65 formed in a connection plug 67 ofthe conductor assembly 27. A retaining ring 68 seats over the taperedcollar 109 to generally close the rear end 107 of the handle housing101. As seen in FIGS. 4 and 6, the handle housing 101 includes a pair ofinternal arcuate ribs 111 extending radially inward from the innersurface of the handle housing. These ribs 111 extend circumferentiallyabout the inner surface of the handle housing 101 to longitudinallylocate and retain a slide bearing 71 within the handle housing.

The handle housing 101 is configured adjacent its front end 113 as acylindrical mount 115 for rotatably mounting the annular actuator 37 onthe handle housing. A shoulder 117 (FIGS. 4 and 18) is formed in theouter surface of the mount 115 to function as a stop to facilitatelongitudinal positioning of the annular actuator 37 on the handlehousing 101. The shoulder 117 also accommodates a suitable sealing ring119 (e.g., an elastomeric gasket or O-ring; FIGS. 4 and 6) to seal theinterface between the annular actuator 37 and the handle housing 101. Anopening 121 (FIG. 6) is formed in the bottom half 105 of the handlehousing 101 at the cylindrical mount 115 to facilitate operativeconnection of the annular actuator 37 with the electrode basket 33 viathe worm gear assembly 306 as described in detail later herein.

The handle housing 101 has a proximal or rear end 107 (FIG. 5) to whichthe conductor assembly 27 is connected in any suitable manner. In theillustrated embodiment of FIG. 5, for example, connection is by aninward tapered collar 109 at the rear end 107 of the handle housing 101seating within an annular channel 65 formed in a connection plug 67 ofthe conductor assembly 27. A retaining ring 68 seats over the taperedcollar 109 to generally close the rear end 107 of the handle housing101. As seen in FIGS. 4 and 6, the handle housing 101 includes a pair ofinternal arcuate ribs 111 extending radially inward from the innersurface of the handle housing. These ribs 111 extend circumferentiallyabout the inner surface of the handle housing 101 to longitudinallylocate and retain a slide bearing 71 within the handle housing.

Referring now to FIGS. 9-12, the illustrated worm gear housing 301(broadly, the inner shuttle of the handle 25) is of two-piececonstruction, referenced herein as a top half 303 and a bottom half 305.In other suitable embodiments the worm gear housing 301 may be ofsingle-piece construction, or constructed of more than two pieces. Theworm gear assembly 306 (FIGS. 9 and 12) is positionable longitudinallywithin the worm gear housing 301 and includes a worm gear 307 rotatableon a linear bushing 309. The linear bushing 309 has a head 311, and asmaller diameter shaft 313 extending longitudinally forward from thehead. A pair of locating pins 315 project from the outer circumferenceof the head 311 for seating in a longitudinally extending slot 317 (asillustrated best in FIG. 9) in the top half 303 of the worm gear housing301 to locate and retain the worm gear assembly 306 in the worm gearhousing and to inhibit the head 311 of the worm gear bushing 309 againstrotation relative to the worm gear housing. The slot 317 is sized inlength to permit longitudinal translation of the worm gear assembly 306relative to the worm gear housing 301 in response to rotation of theworm gear 307 on the bushing 309. A distal or front end 319 of thebushing shaft 313 has an annular groove 321 formed therein to facilitatemounting of the worm gear 307 on the bushing 309.

The illustrated worm gear 307 is generally tubular, having a centralchannel 323 for receiving the bushing shaft 313 therein. Catches (notshown) project radially inward of the channel 323 from the inner surfaceof the worm gear 307 for seating in the annular groove 321 of thebushing shaft 313 to mount the worm gear on the bushing for rotation onthe shaft of the bushing. A lever arm 325 extends radially outward fromthe worm gear 307 for operative connection with the annular actuator 37.In particular, the bottom half 305 of the worm gear housing 301 has awindow 327 (FIGS. 6, 10 and 11) through which the worm gear lever arm325 extends when the worm gear assembly 306 is otherwise housed withinthe worm gear housing as illustrated in FIG. 10. A longitudinallyextending groove 329 (FIG. 6) is formed in the inner surface of theannular actuator 37 and is configured to receive the outer end of theworm gear lever arm 325 upon assembly of the handle 25 such thatrotation of the annular actuator drives rotation of the worm gear 307relative to the worm gear housing 301 (and hence the handle 25).

Suitable worm gear threads 331 project outward from the worm gear 301(e.g., two sets of worm gear threads are illustrated in the variousembodiments, such as in FIG. 12) and seat within corresponding guidechannels 333 (one of which is illustrated in FIG. 11) formed in therespective inner surfaces of the top half 303 and bottom half 305 of theworm gear housing 301. The worm gear threads 331 and corresponding guidechannels 333 are configured such that upon rotation of the worm gear 307relative to the worm gear housing 301 (e.g., due to rotation of theannular actuator 37 from an initial or neutral position corresponding tothe collapsed configuration of the electrode basket 33 to a rotatedposition corresponding to the expanded configuration of the electrodebasket), the worm gear assembly 306 moves linearly (i.e.,longitudinally) rearward relative to the worm gear housing.

As best seen in FIG. 4, the shaft 313 of the linear bushing 309 ishollow. A threaded bore 335 extends transversely through the sidewall ofthe bushing head 311, with a substantially smaller bore 337 being formedlongitudinally in the head of the bushing so as to provide communicationbetween the hollow shaft 313 of the bushing 309 and the threaded boreformed in the head of the bushing. In this manner, the pull wire 39associated with the electrode basket 33 extends into the worm gearhousing 301 and through the worm gear 307 and bushing shaft 313. Thepull wire 39 further extends through the smaller bore 337 in the head311 of the bushing 309 into the threaded bore 335. A suitable fasteneror rotatable plug 339 is disposed in the threaded bore 335 and captures(e.g., coils) the pull wire 39 to operatively connect the electrodebasket 33 with the worm gear assembly 306, and hence the annularactuator 37 via the lever arm 325. The plug 339 also facilitatespredetermined tensioning of the pull wire 39, e.g., upon assembly orsubsequent adjustment of the handle. A notch 308 (FIG. 10) is formed inthe bottom half 305 of the worm gear housing 301 to provide access tothe plug 339 even after assembly of the worm gear housing and barrelhousing 201.

In operation, rotation of the annular actuator 37 from its initialposition to its rotated position causes the worm gear assembly 306 totranslate longitudinally rearward relative to the worm gear housing 301,thus further tensioning the pull wire 39 (i.e., broadly, acting on thecontrol line) to effect expansion of the electrode basket 33 asillustrated in FIG. 3. Rotation of the annular actuator 37 in theopposite direction releases the additional tension in the pull wire 39to thereby allow the electrode basket 33 to return to its collapsedconfiguration (FIG. 1).

With general reference now to FIGS. 4, 6 and 15-21, the barrel housing201 (broadly, the outer shuttle) is also of two-piece construction,including what is referred to herein as a top half 203 (FIG. 15) and abottom half 205 (FIG. 16). In other suitable embodiments, the barrelhousing 201 may be of single-piece construction, or constructed of morethan two pieces. The top half 203 of the barrel housing 201, as bestillustrated in FIG. 15, includes a guide slot 207 for receiving alocating tab 341 (FIGS. 6, 9 and 9A) that projects radially outward fromthe outer surface of the top half 303 of the worm gear housing 301. Thisguide slot 207 is sized in length to accommodate sliding movement of thelocating tab 341—and hence the worm gear housing 301—relative to thebarrel housing 201. A second locating tab 209 (FIG. 15) extends radiallyinward from the inner surface of the top half 203 of the barrel housing201—in longitudinally spaced relationship with the guide slot 207—and isreceivable in a corresponding slot 343 (FIGS. 6 and 9) in the top half303 of the worm gear housing 301. A third locating tab (not shown)extends radially inward from the inner surface of the top half 103 ofthe handle housing 101 and is receivable in a corresponding slot 211(FIGS. 6 and 15) in the top half 203 of the barrel housing 201. Locatingthe various tabs 341, 209 (the third tab, projecting from the handlehousing 101, not being shown) within the corresponding slots 207, 343,211 in this manner also inhibits relative rotation of the respectivehousings 301, 201, 101 following assembly of the handle 25.

The illustrated barrel housing 201 has a longitudinally proximal or rearend 213, and a distal or front end 215. As seen best in FIGS. 17, 18 and21A, a segment 217 of the barrel housing 201 adjacent its rear end 213is sized in cross-section (e.g., in diameter in the illustratedembodiment) for slidable disposition within the slide bearing 71 tocentrally position the barrel housing within the handle housing 101while permitting sliding movement of the barrel housing (i.e., the outershuttle) relative to the handle housing. An annular groove 219 is formedin the barrel housing segment 217 for seating an elastomeric sealingring 221, such as an O-ring or other suitable sealing ring. The sealingring 221 outer diameter is sized for sliding contact of the sealing ringwith the inner surface of the slide bearing 71 upon sliding movement ofthe barrel housing 201 relative to the handle housing 101.

In a more particular embodiment, the elastomeric sealing ring 221 isgenerally loosely retained within the annular groove 219 of the barrelhousing 201. Upon assembly of the barrel housing 201 and sealing ring221 into the handle housing 101 (and hence in the slide bearing 71), theradially outer surface of the sealing ring is compressed by the slidebearing to generate friction between the sealing ring and the slidebearing to facilitate retention of the barrel housing at generally anyposition along the possible longitudinal travel of the barrel housingrelative to the handle housing. In one particularly suitable embodiment,the friction between the sealing ring 221 and slide bearing 71 issufficient to retain the barrel housing 201 at a desired longitudinalposition, but sufficiently loose enough to permit the operator of thecatheter system 21 to move the barrel housing the slide actuator 41(e.g., to deflect the catheter shaft 29) with one hand.

As one example, the elastomeric sealing ring 221 may be suitablyconstructed, and more suitably molded, of silicone. It is understood,though, that the sealing ring 221 may be constructed of another suitableelastomeric material or combination of materials without departing fromthe scope of this disclosure. The slide bearing 71 is suitably ofsingle-piece molded plastic. For example, in one suitable embodiment theslide bearing 71 is constructed of an acetal material. In otherembodiments, however, the slide bearing 71 may be made of other suitablematerials or combination of materials.

As illustrated in FIG. 21A, the inner surface (e.g., inner diameter) ofthe slide bearing 71 according to one embodiment is chamfered 51 at itslongitudinal back end and defines a neutral or initial position of thebarrel housing 201 (corresponding to the undeflected configuration ofthe catheter). The chamfer 51 provides compression relief of the sealingring 221 in the neutral position of the barrel housing 201 to inhibitcompression set over long periods of non-use of the catheter system 21.The inner surface of the illustrated slide bearing 71 is also chamfered53 at its longitudinal front end to provide a detent at the maximumlongitudinal travel of the barrel housing 201 to thereby providefeedback to the operator that the barrel housing is at the maximumlongitudinal travel thereof.

The bottom half 205 of the barrel housing 201 includes a window 223(FIGS. 6 and 16) formed therein to accommodate passage of the worm gearlever arm 325 therethrough (see, e.g., FIG. 17). The window 223 includesa notch 224 (FIG. 16) that aligns with the notch 308 (FIG. 10) of thebottom half 305 of the worm gear housing 301 to provide access to theplug 339 for adjusting the tension in the pull wire 39 even afterassembly of the worm gear housing and barrel housing 201.

The top half 203 and bottom half 205 of the barrel housing 201 also haverespective, opposed pin seats 225 (FIGS. 15 and 16) extending generallytransversely inward from the respective inner surfaces thereof. Thesepin seats 225 are configured to pivotally retain the pinion member 401(FIG. 17) in the barrel housing 201 for longitudinal movement along withthe barrel housing (i.e., the outer shuttle) relative to the handlehousing 101.

With particular reference to FIGS. 13 and 14, the pinion member 401comprises a hub 403, a primary (broadly, a first) pinion gear 405disposed on one transverse side of the hub, and a pair of secondarypinion gears 407 (broadly, a second or at least one second pinion gear)disposed on a transverse side of the hub opposite the primary piniongear. A pin 409 extends outward from each of the respective secondarypinion gears 407 as illustrated in FIG. 14 to define a pivot or rotationaxis Z of the pinion member 401. Upon assembly of the handle 25, thepins 409 seat within the respective pin seats 225 of the barrel housing201 to pivotally secure the pinion member 401 in the barrel housing 201while permitting pivoting movement of the pinion member relative to thebarrel housing about the pivot axis Z.

As seen best in FIG. 14, the primary pinion gear 405 comprises twoparallel rows of gear teeth 411. It is understood that in alternativeembodiments the primary pinion gear 405 may comprise a single row ofgear teeth extending the width of the primary pinion gear, or a singlerow of gear teeth extending less than the entire width of the primarypinion gear. In other alternative embodiments, the primary pinion gear405 may comprise more than two rows of gear teeth. A respectivecorresponding rack 127 (one of which is illustrated in FIGS. 4 and18-21, the other of which is not shown but is identical to thatillustrated in these Figures) extends inward from the inner surface ofeach of the top half 103 and bottom half 105 of the handle housing 101.Accordingly, upon sliding movement of the barrel housing 201 (i.e., theouter shuttle) relative to the handle housing 101, the interengagementof the primary pinion gear teeth 411 with the corresponding racks 127 onthe handle housing 101 cause the pinion member 401 to pivot relative tothe barrel housing 201 about the pivot axis Z of the pinion member froman initial or neutral position (FIG. 20) toward a maximum pivotedposition (FIG. 21).

A central bore 413 (FIG. 13) extends at least into, and in theillustrated embodiment it extends through (e.g., from the top to thebottom of), the hub 403 of the pinion member 401. The bore 413 isthreaded and receives a suitable fastener or rotatable plug 415 therein.A substantially smaller bore 417 extends transversely through the sideof the pinion member hub 403 into open communication with the centralbore 413. As illustrated in FIGS. 4 and 17, the pull wire 43 associatedwith deflection of the catheter shaft 29 extends into the handle housing101, into the barrel housing 201 (and worm gear housing 301), and thenthrough the smaller bore 417 in the hub 403 of the pinion member 401into the central bore 413. The plug 415 is used to coil the pull wire 43to thereby selectively tension the pull wire to a predetermined desiredtension. Accordingly, the catheter shaft 29 is operatively connected tothe barrel housing 201 (i.e., the outer shuttle) via the pinion member401.

As illustrated in FIGS. 9 and 10, the pinion member 401 is disposed inpart within the worm gear housing 301 upon assembly of the worm gearhousing, with the pins 409 extending outward from windows 345 formed inthe worm gear housing such that pins can seat in the respective pinseats 225 of the barrel housing 201. An opening 346 (FIGS. 10 and 10A)in the bottom half 305 of the worm gear housing 301 and correspondingopening 226 (FIG. 16) in the bottom half 205 of the barrel housing 201provide access to the plug 415 (see, e.g., FIG. 10) to permit adjustmentof the tension of the pull wire 43 even after assembly of the worm gearhousing and barrel housing.

The central bore 413 of the pinion member 401 is offset from the pins409 (and hence the pivot axis Z) such that upon pivoting movement of thepinion member about its pivot axis, the central bore 413 and plug 415 towhich the pull wire 43 is connected orbits about the pivot axis of thepinion member. More particularly, in the initial or neutral position(FIGS. 17-20) of the pinion member 401 corresponding to the undeflectedconfiguration of the catheter shaft 29, the primary pinion gear 405 andhence the central bore 413 and plug 415 of the pinion member are at amore longitudinally forward position relative to the barrel housing 201.In particular, as illustrated best in FIGS. 17 and 20, to facilitateproper alignment of the pinion member 401 in its neutral position a post318 extends within the worm gear housing 301 between the opposed tophalf 303 and bottom half 305 of the worm gear housing. In the neutralposition of the pinion member 401, the primary pinion gear 405 abutsagainst the post, with the rearwardmost teeth of the primary pinion gearintermeshed with the rearwardmost teeth of the rack 127 of the housing101.

Upon sliding movement of the barrel housing (i.e., the outer shuttle) ina forward direction relative to the handle housing 101, theinterengagement between the primary pinion gear teeth 411 and the racks127 on the handle housing cause the pinion member to pivot about itspivot axis Z such that the primary pinion gear and hence the centralbore 413 and plug 415 move in a generally rearward direction relative tothe barrel housing 201 as illustrated in FIG. 21. Because the cathetershaft 29 (to which the pull wire 43 is connected) is being movedlongitudinally forward along with the barrel housing 201 but the plug415 (to which the pull wire 43 is also connected) is pivoted rearwardrelative to the barrel housing, tension in the pull wire 43 increasesand thus causes the deflectable segment of the catheter shaft 29 todeflect towards its maximum deflected configuration. Rearward movementof the barrel housing 201 causes the pinion member 401 to pivot backtoward its neutral position, thus releasing the additional tension inthe pull wire 43 to allow configuration of the catheter shaft 29 backtoward its undeflected configuration.

The front end 215 of the barrel housing 201 includes a pair of detents227 (FIG. 8) extending radially outward from the housing. The slideactuator 41, as illustrated in FIGS. 6-8, has a central opening 55 sizedfor receiving the front end 215 of the barrel housing 201 therein. Apair of opposed guide channels 57 (FIG. 8) extend longitudinally in theinner surface of the slide actuator 41 to accommodate the outwardextending detents 227 of the barrel housing 201. A pair of shoulders 59(FIG. 8) are formed on the inner surface of the slide actuator 41adjacent the longitudinally front end thereof.

To operatively connect the slide actuator 41 to the barrel housing 201(i.e., the outer shuttle), the slide actuator is placed on the front end215 of the barrel housing, with the detents 227 of the barrel housingdisposed in and sliding along the channels 57 in the inner surface ofthe slide actuator. Upon further placement of the slide actuator 41 ontothe barrel housing 201, the detents 227 become positioned just forwardof the shoulders 59 formed in the inner surface of the slide actuator.The slide actuator 41 is then rotated relative to the barrel housing 201so that the detents 227 seat on the shoulders 59 of the slide actuatorto interlock and hence operatively connect the slide actuator to thebarrel housing 201. In this manner, sliding movement of the slideactuator 41 relative to the handle housing 101 as illustrated in FIG. 2operatively slides the barrel housing (i.e., the outer shuttle)therewith, and hence pivots the pinion member 401 relative to the barrelhousing to selectively configure the catheter between its undeflectedand deflected configurations. It is understood that an outer shuttle maybe configured other than as a housing such as the barrel housing 201without departing from the scope of this disclosure, as long as the pullwire 43 (i.e., the control wire) associated with deflection of thecatheter is operatively coupled with the outer shuttle such thatmovement of the outer shuttle relative to the handle acts on thecatheter shaft 29, i.e., deflects the catheter shaft.

The catheter system 21 thus allows deflection of the catheter shaft 29independent of selective configuration of the electrode basket 33between its collapsed and expanded configurations using the annularactuator 37. However, because the worm gear housing 301 and worm gearassembly 306 (to which the electrode basket pull wire 39 is connected)are disposed within and carried by the barrel housing 201, the worm gearassembly and hence the connection point at which the electrode basketpull wire 39 is connected to the handle 25 move longitudinally forwardrelative to the handle housing 101 along with the barrel housing inresponse to actuation of the slide actuator 41. As a result, regardlessof whether the electrode basket 33 is in its collapsed configuration orits expanded configuration, the length of the pull wire 39 from theelectrode basket to the connection point on the worm gear assembly 306is relatively shortened in response to actuation of the slide actuator41 to deflect the catheter shaft 29. Accordingly, absent compensationfor this shift, the pull wire 39 associated with the electrode basket 33is susceptible to decreased tension and even the possibility of slack inthe pull wire upon deflection of the catheter shaft 29. To this end,according to one embodiment herein the pull wire 39 associated with theelectrode basket 33 is responsive to adjustment of the catheter shaft 29configuration to thereby inhibit slack from forming in the electrodebasket pull wire.

More particularly, in the illustrated embodiment the worm gear housing301—disposed within the barrel housing 201 and together with the wormgear assembly defining an inner shuttle of the handle 25—includes a rack347 (FIGS. 9, 9A, 10 and 10A) formed along respective edges of thewindows 345 formed in top half 303 and bottom half 305 of the worm gearhousing 301. As illustrated in FIGS. 9 and 10, the secondary piniongears 407 interengage the respective racks 347 upon assembly of the wormgear housing 301 and barrel housing 201. The secondary pinion gears 407and the corresponding racks 347 on the worm gear housing 301 areconfigured and arranged such that upon pivoting of the pinion member 401relative to the barrel housing 201, the worm gear housing 301 andcorresponding worm gear assembly 306 (i.e., the inner shuttle) aredriven to move in a direction opposite the direction of movement of thebarrel housing (i.e., longitudinally rearward in the illustratedembodiment). Stated another way, because the worm gear housing 301 andworm gear assembly 306 (i.e., the inner shuttle) are disposed within thebarrel housing 201 and is thus moved longitudinally forward with thebarrel housing relative to the handle housing 101 upon actuating theslide actuator 41 (and hence the barrel housing) forward, the secondarypinion gears 407 cause the worm gear housing 301 and assembly 306 tomove longitudinally forward a distance less than the forward traveldistance of the barrel housing. This is visible in FIG. 21 by the gap129 formed between the barrel housing 201 and the worm gear housing 301when the barrel housing is moved to its maximum travel positioncorresponding to the deflected configuration of the catheter shaft 29.

By reducing the longitudinally forward travel of the worm gear housing301 and assembly 306 (i.e., the inner shuttle) relative to the forwardtravel of the barrel housing 201 (i.e., the outer shuttle), slack isinhibited from forming in the electrode basket pull wire. As such, theworm gear housing 301 and assembly 306 (i.e., the inner shuttle) alongwith the secondary pinion gears 407 together broadly define acompensator assembly to which the electrode basket pull wire 39 (i.e.,the control line) is operatively coupled and is responsive to actuationof the slide actuator 41 (and hence deflection of the catheter shaft 29)to inhibit slack from forming in the electrode basket pull wire.However, the worm gear housing 301 and assembly 306 must move forwardsome distance along with the barrel housing 201 to avoid increasingtension in the electrode basket pull wire 39 to a tension that wouldunintentionally expand the electrode basket. It is understood that inother embodiments a suitable compensator assembly other than a shuttleand pinion gear arrangement may be used to inhibit slack from forming inthe electrode basket pull wire (i.e., the control line), as long as thecompensator is responsive to actuation of the slide actuator 41 (i.e.,deflection of the catheter shaft 29) to inhibit slack from forming inthe electrode basket pull wire.

In one embodiment, the difference between the barrel housing 201 traveland the worm gear housing 301 travel is at least in part a function ofthe gear ratio between the primary pinion gear 405 and the secondarypinion gears 407, e.g., in view of the respective distances of the gearsfrom the pivot axis Z of the pinion member 401. For example, in theillustrated embodiment the primary pinion gear 405 is suitably spacedfrom the pivot axis Z a distance greater than the distance of thesecondary pinion gears 407 from the pivot axis. It is understood,however, that the gear ratio may be other than as described abovewithout departing from the scope of this disclosure, as long as it issufficient to inhibit slack from forming in the electrode basket pullwire 39.

With reference now to FIGS. 7, 8 and 22-27, in one embodiment, thecatheter 23 and more particularly the catheter shaft 29 is suitablyconnected to the handle 25 by a collar 131 (broadly a connector) andflex relief member 133. It is understood, however, that the flex reliefmember 133 may be omitted without departing from the scope of thisdisclosure. As illustrated in FIGS. 24-27, the collar 131 is generallytubular, having a frustoconical outer surface 135 tapering inward incross-section from a longitudinally rear end 137 to a front end 139thereof, and a central channel 141 extending the length of the collarand defining an inner surface of the collar. The central channel 141includes a first segment 143 extending longitudinally from the front end139 of the collar 131 and having a relatively greater transversecross-section (i.e., diameter) to define a chamber for receiving thecatheter shaft 29 into the collar, and a second segment 145 extendinglongitudinally from the rear end 137 of the collar and having asubstantially smaller transverse cross-section than the first segment ofthe channel. A shoulder 147 is formed within the channel 141 by thereduced cross-section from the first to the second channel segments 143,145 to thereby define a seat against which one end (i.e., the rear end)of the catheter shaft 29 abuts upon insertion of the catheter shaft intothe collar 33 as illustrated best in FIGS. 7, 8 and 27.

In the illustrated embodiment, the first segment 143 of the channel 141within collar 131 increases gradually (i.e., tapers outward) intransverse cross-sectional dimension (e.g., diameter) from the seat 147to the front end 139 of the collar. More particularly, the diameter ofthe channel 141 at the seat 147 against which the shaft 29 abuts issubstantially sized relative to the outer diameter of the catheter shaftto facilitate a close contact of the catheter shaft against the innersurface of the collar when the shaft abuts against the seat within thechannel. Gradually increasing the transverse cross-sectional dimensionof the channel 141 as it extends toward the front end 139 of the collar131 provides a small clearance between the catheter shaft and the innersurface of the collar along a segment of the collar channel.

A port 149 is formed in and extends transversely through the sidewall ofthe collar 131 intermediate the front and rear ends 139, 137 of thecollar, and more particularly at location along the channel segmentwhere this is a small clearance between the inner surface of the collarand the outer surface of the catheter shaft. Upon assembly of thecatheter shaft 29 with the collar 131, the catheter shaft is insertedlongitudinally inward into the collar channel 141 at the front end 139of the collar until the end of the catheter shaft abuts against the seat147 formed within the channel. A suitable adhesive, such as a UVadhesive, is injected through the fill port 149 into the channel 141.The adhesive flows at least circumferentially around the outer surfaceof the catheter shaft 29 and in some embodiments also longitudinallywithin the segment of the channel 141 to fill the spacing between thecatheter shaft outer surface and the relatively wider portion of thechannel near the front end 139 of the collar (as well as some portionsof the channel rearward of the fill port) to provide a circumferentialbond between the collar and the catheter shaft. A uniform fill iscontrolled by the adhesive dispensing time. The collar 131 is suitablyconstructed of a material that permits the throughpassage of UV energy,such as a polycarbonate or other suitable material, to facilitate curingof the UV adhesive within the collar.

An annular flange 151 circumscribes the outer surface 135 of the collar131 longitudinally inward from the rear end 137 of the collar, and moreparticularly at a location corresponding generally to the seat 147formed within the collar channel 141. The flange 151 provides a stop forlimiting longitudinal insertion of the collar 131 into the flex reliefmember 133 as best illustrated in FIGS. 7, 8 and 27. A pair oflongitudinally extending flanges 153 (each broadly defining aprojection) extend on the outer surface 135 of the collar 131 from theannular flange 151 to the front end 139 of the collar on opposite sidesof the collar. These longitudinally extending flanges 153 are receivedin corresponding grooves 161 (FIGS. 22 and 23) of the flex relief member133 as described in further detail below upon insertion of the collar131 into the flex relief member to inhibit rotation of the collar (i.e.,to provide torque resistance) relative to the flex relief member.

It is understood that a projection extending outward from the outersurface 135 of the collar 131 may be configured other than as alongitudinally extending flange 153, such as in the form of a post orother suitable projection. It is also contemplated that a singleprojection, or more than two projections, may be used within the scopeof this disclosure. It is also understood that the catheter shaft 29 maybe connected to the handle 25 in another suitable manner withoutdeparting from the scope of this disclosure.

With reference to FIGS. 22, 23 and 27, the flex relief member 133 isgenerally tubular, having a central channel 163 extending the length ofthe flex relief member, e.g., from an open front end 165 to an open rearend 167 of the flex relief member. The central channel 163 of theillustrated flex relief member 133 comprises three particular segments.A collar housing segment 169 of the channel 163 extends longitudinallyforward from the rear end 167 of the flex relief member 133, and isconfigured in accordance with the outer surface of the collar 131 so asto receive the collar into the collar housing segment in a generallyclose fitting relationship with the flex relief member (see, e.g., FIG.27). A seat 171 is formed generally at the rear end 167 of the flexrelief member 133 to accommodate the annular flange 151 of the collar131 to thereby facilitate proper longitudinal insertion of the collarinto the flex relief member.

A grip segment 173 of the flex relief member channel 163 extends inwardfrom the open front end 165 of the flex relief member 133 and is sizedin transverse cross-section (e.g., diameter) for a close contact fitwith the catheter shaft 29 within the flex relief member. In thismanner, the catheter shaft 29 is inhibited against flexing at or nearthe collar 131 so as to inhibit the catheter shaft from beinginadvertently disconnected or pulled out from the collar. Anintermediate segment 175 of the flex relief member channel 163 extendslongitudinally between the grip segment 173 and the collar housingsegment 169 and is sized in transverse cross-section relatively largerthan the cross-section of the catheter shaft 29. However, it iscontemplated that the intermediate segment 175 could be sized for acloser fit of the catheter shaft 29 with the flex relief member 133along this segment of the channel 163.

A mounting portion 177 of the flex relief member 133 is configuredadjacent the rear end 167 thereof for being clamped by the barrelhousing 201 of the handle 25 to retain the flex relief member on thehandle. The illustrated mounting portion 177 includes a pair ofgenerally square rib elements 179 disposed on opposite sides of the flexrelief member 133. Corresponding pockets 229 (FIGS. 15 and 16) aredisposed in the barrel housing 201 adjacent the front end 215 thereoffor receiving the square rib elements 179 of the flex relief member 133.This facilitates alignment of the flex relief member 133 in the barrelhousing 201 and inhibits rotation of the flex relief member relative tothe barrel housing following assembly of the handle 25. An annulargroove 181 is formed in the outer surface of the flex relief member 133at the front end of the mounting portion 177 to receive a transverselyinward extending flange 231 disposed at the front end 215 of the barrelhousing 201 as illustrated best in FIGS. 7 and 8 to thereby positivelyretain the flex relief member on the barrel housing.

A generally frustoconical closure member 183 circumscribes the flexrelief member 133 forward of the mounting portion 177 and is sized intransverse cross-section to seat within the front end of the slideactuator 41 to generally close the front end of the handle 25 uponassembly of the handle to thereby inhibit dirt or other debris fromgetting into the handle.

Although certain embodiments of this disclosure have been describedabove with a certain degree of particularity, those skilled in the artcould make numerous alterations to the disclosed embodiments withoutdeparting from the spirit or scope of this disclosure. All directionalreferences (e.g., upper, lower, upward, downward, left, right, leftward,rightward, top, bottom, above, below, vertical, horizontal, clockwise,and counterclockwise) are only used for identification purposes to aidthe reader's understanding of the present disclosure, and do not createlimitations, particularly as to the position, orientation, or use of thedisclosure. Joinder references (e.g., attached, coupled, connected, andthe like) are to be construed broadly and may include intermediatemembers between a connection of elements and relative movement betweenelements. As such, joinder references do not necessarily infer that twoelements are directly connected and in fixed relation to each other. Itis intended that all matter contained in the above description or shownin the accompanying drawings shall be interpreted as illustrative onlyand not limiting. Changes in detail or structure may be made withoutdeparting from the spirit of the disclosure as defined in the appendedclaims.

When introducing elements of the present disclosure or the preferredembodiment(s) thereof, the articles “a”, “an”, “the”, and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including”, and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements.

As various changes could be made in the above constructions withoutdeparting from the scope of the disclosure, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:
 1. A catheter system comprising: a handle comprising a housing having a longitudinal axis; a catheter connected to the handle and having a component operatively connected to the handle; an actuator associated with the handle for selectively adjusting at least one characteristic of the catheter component, the actuator comprising a cylindrical shuttle disposed at least in part within the housing and moveable longitudinally relative to the housing, the catheter component being operatively coupled to the shuttle such that longitudinal movement of the shuttle relative to the housing adjusts the at least one characteristic of the catheter component, the shuttle having an outer surface and an annular groove formed in said outer surface, and an elastomeric ring seated in the annular groove; and an annular slide bearing retained in the housing, the shuttle being in part disposed in the slide bearing at the annular groove of the shuttle with the elastomeric ring in frictional contact with an inner surface of the slide bearing, wherein the inner surface of the slide bearing compresses the elastomeric ring and the compressed elastomeric ring frictionally retains the shuttle at a selected longitudinal position relative to the housing corresponding to a selected adjustment of the at least one characteristic of the catheter component, wherein the slide bearing has a longitudinally front end and a longitudinally rear end, the inner surface of the slide bearing being chamfered at least at one of the longitudinally rear end of the inner surface of the slide bearing and the longitudinally front end of the inner surface of the slide bearing such that in a longitudinal position of the shuttle in which the elastomeric ring is disposed at the chamfered inner surface of the slide bearing, the chamfered inner surface of the slide bearing decreases the compression of the elastomeric ring, and wherein the shuttle is positionable between a maximum longitudinally distal position corresponding to the elastomeric ring being positioned at the longitudinally front end of the slide bearing and a maximum longitudinally proximal position corresponding to the elastomeric ring being positioned at the longitudinally rear end of the slide bearing, wherein the housing of the handle has a pair of longitudinally spaced annular ribs secured thereto within the housing, the annular ribs configured to prevent longitudinal movement of the slide bearing within the housing.
 2. The catheter system of claim 1, wherein the front end and the rear end of the slide bearing define a maximum longitudinal travel of the shuttle relative to the handle housing, the inner surface of the slide bearing being chamfered at both the front end and the rear end of the slide bearing and reducing compression of the elastomeric ring to provide a tactile indication to an operator of the catheter system upon sliding movement of the shuttle to either of the front end and the rear end of the slide bearing.
 3. The catheter system of claim 1, wherein the elastomeric ring is constructed at least in part of silicone.
 4. The catheter system of claim 3, wherein the slide bearing is constructed at least in part of an acetal material.
 5. The catheter system of claim 1, wherein the annular groove of the outer surface of the shuttle has a cross-sectional length extending longitudinally of the shuttle, the elastomeric ring having a cross-sectional dimension that is less than the cross-sectional length of the annular groove such that the elastomeric ring seats loosely within the annular groove.
 6. The catheter system of claim 5, wherein the shuttle has an outer diameter at the annular groove, the elastomeric ring having an inner diameter that is greater than the outer diameter of the shuttle at the annular groove such that the elastomeric ring further seats loosely within the annular groove.
 7. The catheter system of claim 1, wherein the slide bearing has an annular flange extending radially outward from the slide bearing that contacts an inner surface of the housing and centers the slide bearing in the housing.
 8. A catheter system comprising: a handle comprising a housing having a longitudinal axis, a catheter connected to the handle and having a component operatively connected to the handle; an actuator associated with the handle for selectively adjusting at least one characteristic of the catheter component, the actuator being digitally manipulatable by an operator using a single hand, the actuator being adjustable from a first position corresponding to the at least one characteristic of the catheter component to a second position corresponding an adjustment of the at least one characteristic of the catheter component, the actuator being frictionally retained in at least one of the first position and the second position thereof, wherein the actuator is frictionally retained in the first position and the second position thereof by frictional engagement between the actuator and the handle housing, and wherein the actuator is positionable at any position between said first and second positions of the actuator and is frictionally retained in said any position with a first frictional engagement between an elastomeric ring associated with the actuator and a constant inner diameter of a central positioning element associated with the handle housing; and a tactile indicator comprising a second frictional engagement having reduced friction between the elastomeric ring associated with the actuator and a chamfer of the central positioning element associated with the handle housing, indicating that the actuator is in the first position, wherein the housing of the handle has a pair of longitudinally spaced annular ribs secured thereto within the housing, the annular ribs configured to prevent longitudinal movement of the central positioning element associated with the handle housing within the housing.
 9. The catheter system of claim 8, wherein the actuator is slidable longitudinally of the housing between said first and second positions.
 10. The catheter system of claim 8, further comprising at least one additional tactile indicator capable of indicating that the actuator is in the second position.
 11. The catheter system of claim 10, wherein the at least one additional tactile indicator comprises a third frictional engagement having reduced friction between the elastomeric ring associated with the actuator and a second chamfer of the central positioning element associated with the handle housing. 